1. Field of the Invention
This invention relates generally to the field of chemical reactions. More specifically, the invention relates to methods of making ketones incorporating high shear mixing.
2. Background of the Invention
Dialkyl ketones are important solvents and intermediates for organic syntheses. For example, 3-pentanone (diethyl ketone) is an excellent solvent for paints. Furthermore, 3-pentanone is used in numerous syntheses, for example the preparation of trimethylphenol and of vitamin E.
Dialkyl ketones are obtainable via a wide variety of synthetic routes, for instance by ketonization of carboxylic acids or aldehydes or by oxidation of secondary alcohols, of olefins or of alkanes. Disadvantages of these synthetic routes are the use of expensive intermediates (carboxylic acids, aldehydes, secondary alcohols, olefins having a central double bond) and often unsatisfactory selectivities and yields in the oxidation of olefins and alkanes.
A further synthetic route is reductive carbonylation of α-olefins (olefins having a terminal double bond) in the presence of hydrogen, water or compounds having a reducing action, e.g. alcohols. Carbonylation of carbon monoxide and hydrogen is well known in the art. See e.g. U.S. Pat. No. 4,602,116 (describing carbonylation in the presence of triruthenium dodecacarbonyl at a pressure of preferably from 1000 to 2500 psig), herein incorporated by reference in its entirety for all purposes. However, other methods have focused on improving the catalysts used in carbonylation. Disadvantages of existing carbonylation processes are the unsatisfactory stability of the catalyst systems and the high pressure necessary in carrying out the carbonylation.
Consequently, there is a need for accelerated methods for preparing dialkyl ketones at lower pressures regardless of the catalyst composition.